Added zero_nil to Quantity form and import

app/controllers/body_trackers_controller.rb

@@ -29,6 +29,8 @@ class BodyTrackersController < ApplicationController
         attrs = q.attributes.except('id', 'project_id', 'parent_id', 'lft', 'rgt',
                                     'created_at', 'updated_at')
         attrs['parent'] = q.parent ? available[[q.parent.name, q.parent.domain]] : nil
+        attrs['formula_attributes'] = q.formula.attributes.except('id', 'quantity_id',
+                                                                  'created_at', 'updated_at')
         obj = @project.quantities.create(attrs)
         available[[q.name, q.domain]] = obj
       end

app/views/quantities/_form.html.erb

@@ -13,6 +13,7 @@
   <p><%= f.text_field :description, style: "width: 100%;" %></p>
   <%= f.fields_for :formula do |ff| %>
     <p><%= ff.text_field :code, placeholder: t('.formula_placeholder'),
-        style: "width: 100%;" %></p>
+      style: "width: 100%;" %></p>
+    <p><%= ff.check_box :zero_nil, {label: ''} %><%= t('.zero_nil') %></p>
   <% end %>
 </div>